Stress management is particularly important for healthcare of modern people. In stress research, heart-rate variability (HRV), indicating the change of time intervals in successive heart beats, significantly contributed due to its close relationship with autonomic nervous system. However, the adaptive response to stress, also known as stress resilience, has not been studied much yet. We collected electrocardiogram during mental and physical stress, experimentally designed by mental arithmetic tasks and physical activities for 14 healthy subjects. As a result, we found that resting HRV parameters, particularly associated with the parasympathetic activity, had significant positive correlations with reactivity and recovery from mental and physical stress. These HRV parameters can be used as a measure of stress resilience quantitatively. Our findings suggest that these parameters can help one's stress management by enabling to predict the adaptive response to upcoming stressful events.